Factors that affect the cost of CNC machining
CNC machining is a manufacturing method in which parts are manufactured with the help of digital codes. CNC machining has many advantages, such as in the case of producing the same part, it can improve the speed of part production and reduce a lot of production time.
It can also reduce human error in the manufacturing process because it is computer-controlled. CNC machining is also the first choice for the production of precision and complex parts.
A wide range of materials can be manufactured using CNC machines, such as metals, plastics, and composites. The cost required to process products using CNC depends on different factors.
CNC machining costs may vary due to the following different factors.
1. CNC machine tool cost
Processing costs change with the type of machine. There are mainly two types of machines used to manufacture CNC machined parts, namely 3-axis and multi-axis machines.
Machine cost also depends on various factors such as the size and weight of the machine, speed, power, and machine configuration.
CNC milling is more expensive than other types of machining operations due to the more complex parts involved. The machining cost increases with the increase in the number of axes of the milling machine. For example, in the case of 5-axis machining, it costs more compared to a 3-axis machine.
2. Processing time
The time required for the complete machining of any CNC machining part also plays an important role in the calculation of CNC machining cost, the longer the machining time, the higher the machining cost, which increases the basic setup cost.
Software such as CAM, which requires 3D CAD design models, can provide an estimate of the time it will take to complete a project. Projects with high complexity take more time to complete.
3. Workforce
One of the advantages of CNC machining compared to manual machining is that it reduces the number of labor involved in manufacturing. The main cost of labor is for specialists in machining 3D CAD design models, which increase with the complexity of the desired product.
Even if you need to manufacture more parts, this cost is still the same, which will reduce the machining price per part. However, the additional cost is the labor required to operate the CNC machine, which increases with the time required to complete the machining of the part.
If parts are assembled, completed, and post-processed by hand, additional costs are added to labor costs. If the finished product is delivered from the machine shop to the customer in different locations, additional labor costs will also be added.
4. Shape complexity and size
Machining costs will also increase as the complexity of CNC machining parts increases. More complex parts may require more process operations, different tools, and more production time.
Part features like sharp inner corners, deep cavities, or thin walls can increase CNC machining costs. Designs with simple features are easy to manufacture and also save manufacturing time.
Parts with larger dimensions require more raw materials and time to manufacture, so their cost will be higher than smaller parts.
5. Material costs
Material cost is also essential when calculating CNC machining cost. The price of the final product manufactured by CNC machines depends on the type of material required to manufacture the product.
Because plastic materials are cheaper and less durable, the processing cost of plastic or aluminum materials is lower than that of stainless steel. Since in CNC machines, the material is removed from solid blocks to make 3D objects. Therefore, more raw materials will be required than the final product.
The mechanic buys the material in solid blocks and calculates the cost of each piece. The most commonly used metals in CNC machining are aluminum, stainless steel, and brass.
Due to the economical price of aluminum and excellent processing performance, most machinists use aluminum on CNC machine tools.
Stainless steel and brass have poor machinability relative to aluminum and therefore cost more. Titanium alloy is the most expensive of all these metals, so the processing cost of this metal will be the highest, as it may require some special tools to make parts.
In the case of plastics, most materials are less expensive, the cost of the tools required is lower, and the time required to process plastics such as nylon, delrin and ABS is shorter.
6. Surface treatment
For some products, surface treatment is required, which also leads to an increase in the price of the final product. To enhance the aesthetics of the final product and remove any scratches created during processing, you may need to provide a good finish, such as polishing.
Other finishing processes may also include coating, anodizing, painting, chrome plating, galvanizing, etc. Including any of these finishes adds additional cost to the final product price.
7. Mold cost
In some manufacturing situations, standard tools are useless, so custom tools are required, which also increases the manufacturing cost of using CNC machines.
8. Tolerances
Costs also increase when manufacturing products with tight tolerances because manufacturing parts with tight tolerances requires complex machines. Sometimes you may need to make holes or cavities with tight tolerances, which can create burrs on the surface and will take more time to reduce it.
9. Quantity
The number of orders greatly affects the cost of the final product. It is true that the total cost increases as the finished parts required increase, but the cost per part decreases.
It can also reduce human error in the manufacturing process because it is computer-controlled. CNC machining is also the first choice for the production of precision and complex parts.
A wide range of materials can be manufactured using CNC machines, such as metals, plastics, and composites. The cost required to process products using CNC depends on different factors.
CNC machining costs may vary due to the following different factors.
1. CNC machine tool cost
Processing costs change with the type of machine. There are mainly two types of machines used to manufacture CNC machined parts, namely 3-axis and multi-axis machines.
Machine cost also depends on various factors such as the size and weight of the machine, speed, power, and machine configuration.
CNC milling is more expensive than other types of machining operations due to the more complex parts involved. The machining cost increases with the increase in the number of axes of the milling machine. For example, in the case of 5-axis machining, it costs more compared to a 3-axis machine.
2. Processing time
The time required for the complete machining of any CNC machining part also plays an important role in the calculation of CNC machining cost, the longer the machining time, the higher the machining cost, which increases the basic setup cost.
Software such as CAM, which requires 3D CAD design models, can provide an estimate of the time it will take to complete a project. Projects with high complexity take more time to complete.
3. Workforce
One of the advantages of CNC machining compared to manual machining is that it reduces the number of labor involved in manufacturing. The main cost of labor is for specialists in machining 3D CAD design models, which increase with the complexity of the desired product.
Even if you need to manufacture more parts, this cost is still the same, which will reduce the machining price per part. However, the additional cost is the labor required to operate the CNC machine, which increases with the time required to complete the machining of the part.
If parts are assembled, completed, and post-processed by hand, additional costs are added to labor costs. If the finished product is delivered from the machine shop to the customer in different locations, additional labor costs will also be added.
4. Shape complexity and size
Machining costs will also increase as the complexity of CNC machining parts increases. More complex parts may require more process operations, different tools, and more production time.
Part features like sharp inner corners, deep cavities, or thin walls can increase CNC machining costs. Designs with simple features are easy to manufacture and also save manufacturing time.
Parts with larger dimensions require more raw materials and time to manufacture, so their cost will be higher than smaller parts.
5. Material costs
Material cost is also essential when calculating CNC machining cost. The price of the final product manufactured by CNC machines depends on the type of material required to manufacture the product.
Because plastic materials are cheaper and less durable, the processing cost of plastic or aluminum materials is lower than that of stainless steel. Since in CNC machines, the material is removed from solid blocks to make 3D objects. Therefore, more raw materials will be required than the final product.
The mechanic buys the material in solid blocks and calculates the cost of each piece. The most commonly used metals in CNC machining are aluminum, stainless steel, and brass.
Due to the economical price of aluminum and excellent processing performance, most machinists use aluminum on CNC machine tools.
Stainless steel and brass have poor machinability relative to aluminum and therefore cost more. Titanium alloy is the most expensive of all these metals, so the processing cost of this metal will be the highest, as it may require some special tools to make parts.
In the case of plastics, most materials are less expensive, the cost of the tools required is lower, and the time required to process plastics such as nylon, delrin and ABS is shorter.
6. Surface treatment
For some products, surface treatment is required, which also leads to an increase in the price of the final product. To enhance the aesthetics of the final product and remove any scratches created during processing, you may need to provide a good finish, such as polishing.
Other finishing processes may also include coating, anodizing, painting, chrome plating, galvanizing, etc. Including any of these finishes adds additional cost to the final product price.
7. Mold cost
In some manufacturing situations, standard tools are useless, so custom tools are required, which also increases the manufacturing cost of using CNC machines.
8. Tolerances
Costs also increase when manufacturing products with tight tolerances because manufacturing parts with tight tolerances requires complex machines. Sometimes you may need to make holes or cavities with tight tolerances, which can create burrs on the surface and will take more time to reduce it.
9. Quantity
The number of orders greatly affects the cost of the final product. It is true that the total cost increases as the finished parts required increase, but the cost per part decreases.
